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STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
STATE OF THE CALIFORNIA CURRENT 2012–13: NO SUCH THING AS AN “AVERAGE” YEAR
ABSTRACTThis report reviews the state of the California Cur-
rent System (CCS) between winter 2012 and spring 2013, and includes observations from Washington State to Baja California. During 2012, large-scale climate modes indicated the CCS remained in a cool, produc-tive phase present since 2007. The upwelling season was
delayed north of 42˚N, but regions to the south, espe-cially 33˚ to 36˚N, experienced average to above average upwelling that persisted throughout the summer. Con-trary to the indication of high production suggested by
37
BRIAN K. WELLS, ISAAC D. SCHROEDER, JARROD A. SANTORAFisheries Ecology Division
Southwest Fisheries Science CenterNational Marine Fisheries Service
110 Shaffer RoadSanta Cruz, CA 95060
ELLIOTT L. HAZEN1, STEVEN J. BOGRADEnvironmental Research Division
Southwest Fisheries Science CenterNational Marine Fisheries Service
1352 Lighthouse AvenuePacific Grove, CA 93950-2020
ERIC P. BJORKSTEDTFisheries Ecology Division
Southwest Fisheries Science CenterNational Marine Fisheries Service
110 Shaffer RoadSanta Cruz, CA 95060
and Department of Fisheries Biology
Humboldt State University1 Harpst Street
Arcata, CA 95521
VALERIE J. LOEBMoss Landing Marine Laboratories
8272 Moss Landing RoadMoss Landing, CA 95039
SAM MCCLATCHIE, EDWARD D. WEBER, WILLIAM WATSON,
ANDREW R. THOMPSONFisheries Research Division
Southwest Fisheries Science CenterNational Marine Fisheries Service
8901 La Jolla Shores Drive La Jolla, CA 92037-1508
WILLIAM T. PETERSON, RICHARD D. BRODEUR
Northwest Fisheries Science Center National Marine Fisheries Service Hatfield Marine Science Center
Newport, OR 97365
JEFF HARDING, JOHN FIELD, KEITH SAKUMA, SEAN HAYES,
NATHAN MANTUAFisheries Ecology Division
Southwest Fisheries Science Center National Marine Fisheries Service
110 Shaffer Road Santa Cruz, CA 95060
WILLIAM J. SYDEMAN, MARCEL LOSEKOOT,
SARAH ANN THOMPSONFarallon Institute for
Advanced Ecosystem Research Petaluma, CA 94952
JOHN LARGIERBodega Marine Laboratory
University of California, Davis P.O. Box 247
Bodega Bay, CA 94923
SUNG YONG KIMDivision of Ocean Systems Engineering
Korea Advanced Institute of Science and Technology
Yuseong-gu, Daejeon 305-701 Republic of Korea
FRANCISCO P. CHAVEZMonterey Bay Aquarium Research Institute
7700 Sandholdt Road Moss Landing, CA 95039
CAREN BARCELÓCollege of Earth, Ocean and
Atmospheric Sciences Oregon State University
Corvalis, OR 97331-5503
PETE WARZYBOK, RUSSEL BRADLEY, JAIME JAHNCKE
PRBO Conservation Science 3820 Cypress Drive #1 Petaluma, CA 94954
RALF GOERICKE, GREGORY S. CAMPBELL, JOHN A. HILDEBRAND
Scripps Institute of Oceanography University of California, San Diego
9500 Gilman Drive La Jolla, CA 92093-0205
SHARON R. MELIN, ROBERT L. DELONGNational Marine Fisheries Service Alaska Fisheries Science Center
National Marine Mammal Laboratory NOAA
7600 Sand Point Way N. E. Seattle, WA 98115
JOSE GOMEZ-VALDES, BERTHA LAVANIEGOS,
GILBERTO GAXIOLA-CASTROCentro de Investigación Científica y de
Educación Superior de Ensenada (CICESE) División de Oceanología
Carretera Ensenada Tijuana No. 3918 Zona Playitas, Ensenada
Baja California, México C.P. 22860
RICHARD T. GOLIGHTLY, STEPHANIE R. SCHNEIDER
Department of Wildlife Humboldt State University
1 Harpst Street Arcata, CA 95521
NANCY LOOcean Associates, Inc. and
Fisheries Research Division Southwest Fisheries Science Center National Marine Fisheries Service
8901 La Jolla Shores Drive La Jolla, CA 92037-1508
ROBERT M. SURYAN, AMANDA J. GLADICS, CHERYL A. HORTON
Department of Fisheries and Wildlife Oregon State University
Hatfield Marine Science Center Newport, OR 97365
JENNIFER FISHER, CHERYL MORGAN, JAY PETERSON,
ELIZABETH A. DALYCooperative Institute for Marine Resources Studies Oregon State University
Hatfield Marine Science Center Newport, OR 97365
TOBY D. AUTHPacific States Marine Fisheries Commission
Hatfield Marine Science Center 2030 Marine Science Drive
Newport, OR 97365
JEFFREY ABELLDepartment of Oceanography
Humboldt State University 1 Harpst Street
Arcata, CA 95521
1The first four authors represent members of the SWFSC California Current Integrated Ecosystem Assessment group and worked in equal collaboration on preparation of this report.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
38
observed in the surveys. California sea lion pups from San Miguel Island were undernourished resulting in a pup mortality event perhaps in response to changes in forage availability. Limited biological data were avail-able for spring 2013, but strong winter upwelling coast-wide indicated an early spring transition, with the strong upwelling persisting into early summer.
INTRODUCTIONThis report reviews the oceanographic and ecosys-
tem responses of the California Current System (CCS) between winter 2012 and spring of 2013. Biological and hydrographic data from a number of academic, private, and government institutions have been consolidated and described in the context of historical data (fig. 1). The various institutions have provided data and explanation of the data after an open solicitation for contributions; these contributions are acknowledged in the author list. These data are synthesized here, in the spirit of provid-ing a broader description of the present condition of the CCS. All data are distilled from complex sampling pro-grams covering multiple spatial and temporal scales into a simple figure(s) that might not convey the full com-plexity of the region being studied. As a consequence, we
the climate indices, chlorophyll observed from surveys and remote sensing was below average along much of the coast. As well, some members of the forage assem-blages along the coast experienced low abundances in 2012 surveys. Specifically, the concentrations of all life-stages observed directly or from egg densities of Pacific sardine, Sardinops sagax, and northern anchovy, Engraulis mordax, were less than previous years’ survey estimates. However, 2013 surveys and observations indicate an increase in abundance of northern anchovy. During win-ter 2011/2012, the increased presence of northern cope-pod species off northern California was consistent with stronger southward transport. Krill and small- fraction zooplankton abundances, where examined, were gen-erally above average. North of 42˚N, salps returned to typical abundances in 2012 after greater observed con-centrations in 2010 and 2011. In contrast, salp abundance off central and southern California increased after a period of southward transport during winter 2011/2012. Reproductive success of piscivorous Brandt’s cormorant, Phalacrocorax penicillatus, was reduced while planktivo-rous Cassin’s auklet, Ptychoramphus aleuticus was elevated. Differences between the productivity of these two sea-birds may be related to the available forage assemblage
A
B
C
E
D
F
G
H
I
Latitude
Longitude
IMECOCAL
CalCOFI
CalCOFI Line 67
Newport Hydrographic Line
Trinidad Head Line
Figure 1. Left: Station maps for surveys that were conducted multiple times per year during different seasons to provide year-round observations in the Califor-nia Current System. The CalCOFI survey (including CalCOFI Line 67) were occupied quarterly; the spring CalCOFI survey grid extends just north of San Francisco. The IMECOCAL survey is conducted quarterly or semiannually. The Newport Hydrographic Line was occupied biweekly. The Trinidad Head Line was occupied at biweekly to monthly intervals. Right: Location of annual or seasonal surveys, including locations of studies on higher trophic levels, from which data was included in this report. Different symbols are used to help differentiate the extent of overlapping surveys. A. SWFSC FED midwater trawl survey core region (May–June) B. SWFSC FED midwater trawl survey south region (May–June). C. SWFSC FED salmon survey (June and September) (grey squares). D. NWFSC salmon survey (May, June, and September). E. NOAA/BPA pelagic rope trawl survey (May through September). F. Southeast Farallon Island. G. Castle Rock. H. San Miguel Island. I. Yaquina Head Outstanding Natural Area.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
39
ASSMNT_RPT2_WEB_ONLY_NOV2012BB.pdf). Here, we return to an initial focus of the CalCOFI pro-gram and consider physical and biological signals related to coastal pelagic species. Importantly, the survey designs that we examine are dissimilar and each has unique lim-itations restricting a common interpretation along the CCLME. Therefore, this report should be considered a first examination for instigating more focused explo-ration of potential drivers of the forage community’s dynamics.
This report will focus on data highlighting variability in the forage community with additional (supporting) data provided in the supplement. Some information in the supplement are data that have been presented in pre-vious reports and are included as a reference to an aspect of the “state of the CCS,” which might be of interest beyond the focus here. As in past reports, we begin with an analysis of large-scale climate modes and upwelling conditions in the California Current. Following, the var-ious observational data sampling programs are reviewed to highlight the links between ecosystem structure, pro-cesses, and climate.
focus on the findings of the data and limit our descrip-tions of the methodology to only that which is required for interpretation. More complete descriptions of the data and methodologies can be found in the supplement. Can be found in the supplement (http://calcofi.org/publications/ccreports/568-vol-54-2013.html)
In 1949, the California Cooperative Oceanic Fisheries Investigations program (CalCOFI) was formed to study the environmental causes and ecological consequences of Pacific sardine, Sardinops sagax, variability. Consider-ation of the broader forage communities has been invig-orated by recent fluctuations in the abundance of sardine and another important forage fish, the northern anchovy, Engraulis mordax (Cury et al. 2011; Pikitch et al. 2012). Specifically, there has been a decline in the observed catches of larval, juvenile, and adult northern anchovy reported by the various sampling programs along the CCS (Bjorkstedt et al. 2012). While not unprecedented, with two similar examples since 1993, the estimated Pacific sardine biomass declined from 1,370,000 MT in 2006 to 659,539 MT in July 2012 (http://www.pcouncil .org/wp-content/uploads/MAIN_DOC_G3b_
Figure 2. Time series of monthly mean values for three ocean climate indices especially relevant to the California Current: the multivariate ENSO index (MEI), the Pacific Decadal Oscillation (PDO), and the North Pacific Gyre Oscillation (NPGO) for January 1985–June 2013. Vertical lines mark January 2011, 2012, and 2013.
http://www.pcouncil.org/wp-content/uploads/MAIN_DOC_G3b_ASSMNT_RPT2_WEB_ONLY_NOV2012BB.pdf
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
40
NORTH PACIFIC CLIMATE PATTERNSA basin-scale examination of SST allows for the
interpretation of the spatial evolution of climate pat-terns and wind forcing over the North Pacific related to trends in the basin-scale indices (fig. 2). In the sum-mer of 2012, predominately negative SST anomalies over the western Pacific coincided with anticyclonic wind anomalies. Warmer than normal SST (+1.0˚C) in the central and eastern north Pacific occurred dur-ing a period of anomalous eastward winds in October of 2012. For 2013 the northeast Pacific experienced winter SST anomalies that were slightly cooler than normal (< –0.5˚C), followed by slightly warmer anom-alies (< +0.5˚C) in the spring. SST anomalies across the North Pacific in 2013 (January to June) were positive and were simultaneous with a rise in PDO values from the extreme negative values experienced in 2012. How-ever, SST anomalies along the CCS remained slightly negative (< –0.5˚C) forced by equatorward meridional wind anomalies (fig. S1).
NORTH PACIFIC CLIMATE INDICES The multivariate El Niño Southern Oscillation
(ENSO) index (MEI) (Wolter and Timlin 1998) tran-sitioned from La Niña conditions in summer of 2010 through January 2012 (fig. 2). In the summer of 2012, MEI increased but the values were too low and short-lived to be classified as an ENSO event; the values returned to neutral conditions in the spring of 2013. The Pacific Decadal Oscillation index (PDO) (Mantua and Hare 2002) has been negative (cool in the CCS) coincid-ing with the start of the La Niña in the summer of 2010 (fig. 2). The PDO continued in a negative phase through the summer of 2012, with a minimum in August. After October 2012, the PDO increased to slightly negative values in the winter and spring of 2013. The May 2013 value of the PDO was +0.08 but dropped to a value of –0.78 in June. The North Pacific Gyre Oscillation index (NPGO) (Di Lorenzo et al. 2008) was positive from the summer of 2007 to the spring 2013 with a peak value in July 2012 (fig. 2).
Figure 3. Monthly upwelling index (top) and upwelling index anomaly (bottom) for January 2011–May 2013. Shaded areas denote positive (upwelling-favorable) values in upper panel, and positive anomalies (generally greater than normal upwelling) in lower panel. Anomalies are relative to 1967–2013 monthly means. Units are in m3 s–1 per 100 km of coastline.
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since record highs experienced in 2007. Strong upwell-ing continued into the summer off southern California (33˚N) with CUI estimates at the end of July being the highest since 1999. At 36˚N, the 2012 CUI values at the end of the year were the second highest on record, falling just below the high in 1999. Through mid-2013, CUI values are greater than previously observed records throughout the CCS. While there were signifi-cant regional differences in upwelling in 2012, strong upwelling occurred more widely in the CCS in winter and spring of 2013.
Coastal Sea Surface TemperatureIn 2011, the daily December values of SST were
below average especially at the northern California and Oregon buoys (fig. S3). This is due to upwelling at the start of December; these winds were especially long in duration for the Oregon buoy, with the event lasting over half of the month. Anomalously cool SST values in December 2011 extended into spring of 2012 as mea-sured by all of the buoys. There was very little temper-ature variation between winter of 2011/2012 through spring of 2012. Periods of northerly winds occurred in January and February for the northern buoys with these winds switching directions to southerly in March and April. SST increased for the northern two buoys but the southern buoys showed average temperatures. Only one buoy (St. George, CA) had a complete record of winds in the summer (June–August) of 2012, and the winds
Upwelling in the California CurrentDecember 2011 was marked by anomalously strong
upwelling between 36˚N and 45˚N and substantially weaker downwelling north of 45˚N (fig. 3). This resulted in anomalously low coastal sea levels, as measured by tidal gauges, in December at Neah Bay, WA, South Beach, OR, and Crescent City, CA (fig. 4). Such low coastal sea levels suggests southward transport in win-ter 2011/2012.
By March 2012, upwelling winds north of 39˚N were anomalously low while winds south of 39˚N remained near the climatological mean. Upwelling north of 39˚N did not resume again until May and for summer and fall remained at close to climatological values. In con-trast, south of 39˚N average upwelling prevailed from winter 2011 to April 2012, after which it intensified. Strong upwelling continued off central California until fall. North of 36˚N, high upwelling persisted through winter 2012 and into January–February 2013 (fig. 3).
The cumulative upwelling index (CUI) gives an indi-cation of how upwelling influences ecosystem structure and productivity over the course of the year (Bograd et al. 2009). In the north from 42˚ to 48˚N, the upwelling season in 2012 began early (fig. S2) resulting in average CUI values from January 1 to the beginning of March, but dropped to below long-term average over the spring and summer. The upwelling season also began early in southern and central California (33˚–36˚N) during 2012, with highest levels of the CUI at the end of February
-‐3
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2009
2011
Decembe
r SLH
Ano
malies
Neah Bay South Beach Crescent City San Francisco
Figure 4. Sea level height anomalies measured by tidal gauges during December for the following four locations along the CCS: Neah Bay, WA, South Beach, OR, Crescent City, CA and San Francisco, CA. Horizontal lines mark the values observed in December 2011.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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Figure 5. Maps of mean HF radar meridional surface currents observed December 2011 throughout the CCS 2007–11 (December 2012 was not available for this report). Meridional current speed is indicated by color bar (blue shading indicates southward flow) with units of cm/s.
Figure 6. Aqua MODIS satellite measured chlorophyll a anomalies for March–May averages. The climatology was based on data for the years 2003–13. The black line is the 1000 m isobath.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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were predominately downwelling in direction with only a few days of upwelling winds in June. Towards the end of fall (October–November of 2012) above average SSTs occurred for all of the buoys for which we had data. The winds during this time were downwelling-favorable except for a strong upwelling event in the beginning of December. Cool temperatures were evident in early 2013 and persisted until April for all of the buoys. In late April, SSTs dipped due to a strong upwelling event. The winds in January through June of 2013 have mostly been upwelling-favorable except off Oregon where there have been short periods of downwelling.
High Frequency Radar Surface Current Observations
Surface transport was southward in the northern CCS during December 2011, as observed by high frequency (HF) radar (fig. 5) in support of the upwelling (fig. 3) and sea level (fig. 4) data. For the spring of 2012 sur-face currents observed with HF radar revealed southward currents, developing into marked offshore flow in sum-mer with a general weakening in the fall and a tendency for weak northward flow in winter (see supplement for additional results, fig. S4).
Coast-wide Analysis of ChlorophyllWe used Aqua MODIS satellite measurements to
evaluate spring chlorophyll (anomalies; climatology based on 2003–13) in the surface waters of the CCS for 2011–13 (details in supplement). Surface chloro-phyll anomalies were generally below average north of San Francisco, CA during the spring of 2011, while the spring values of chlorophyll in 2012 were below aver-age south of Cape Mendocino except for increased pro-duction in the Gulf of the Farallones and throughout
T-S at a depth of 50 m at NH 05 October-December
Salinity32.9 33.0 33.1 33.2 33.3 33.4
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T-S at a depth of 50 m at NH-05July-September
Salinity33.60 33.65 33.70 33.75 33.80 33.85 33.90 33.95
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T-S Properties at 50 m depthat NH 05 January-March
Salinity32.4 32.6 32.8 33.0 33.2
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Figure 7. Seasonal mean temperature and salinity at 50 m depth at NH-5 along the Newport Hydrographic Line averaged for summer, fall and winter 2012. Cruises are made biweekly. Numbers adjacent to each data indicate “year.”
Chl
orop
hyll-
a (u
gL-1
)
Figure 8. Chlorophyll a time series off Newport Oregon at station NH5 show-ing that chlorophyll a averaged over the May–September upwelling season, was unusually low in the year 2012, similar to values not seen since 1999 and 2000.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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and warmer years; July–September was cool and fresh. By contrast, during the January to March period of 2013, deep water was the most saline of the time series. Con-comitant with that, the temperature was also one of the two lowest, 2008 being the lowest (fig. 7). Chlorophyll values at five miles off shore (NH5) averaged over May–September were the lowest they have been since 1999 and 2000 (fig. 8).
Examination of the copepod community can help to determine source waters and provide insights into the productivity of the system (Peterson and Keister 2003). Copepods that arrive from the north are cold-water species that originate from the coastal Gulf of Alaska and include three cold-water species: Calanus marshallae, Pseudocalanus mimus, and Acartia longiremis. Copepods that reside in offshore and southern waters (warm-water species) include Paracalanus parvus, Ctenocalanus vanus, Calanus pacificus, and Clausocalanus spp. among others. Copepods are transported to the Oregon coast, either from the north/northwest (northern species) or from the west/south (southern species). The Northern Cope-pod Index (Peterson and Keister 2003) was positive from autumn 2010 through summer 2012. The January and February 2012 values were the highest ever for the index and occurred after the southern transport anom-aly observed in the winter of 2011 (figs. 9 and 4). The
much of the offshore regions south of Point Conception (fig. 6). In spring 2013, chlorophyll was elevated along most of the coast north of Point Conception; south of Point Conception chlorophyll was below average.
REGIONAL SUMMARIES OF HYDROGRAPHIC AND PLANKTONIC DATA
Several ongoing surveys provide year-round hydro-graphic and planktonic observations across the CCS but vary in terms of spatial extent, temporal resolution sur-vey design, and limitations (fig. 1). In the following sec-tion we review recent observations from these surveys from north to south.
Northern California Current: Newport Hydrographic Line
Daily values of SST from the Newport Hydrographic Line showed warm temperature anomalies in June and July 2012, with daily values of temperature anomalies around +3˚C in mid-July. The monthly average anomaly was +1.7˚C for July. SST at hydrographic station NH5 (five miles offshore of Newport) was also above-average over the May–September period with a peak in SST (15.9˚C) observed on 25 June, a value which was the 12th warmest of 450 sampling dates since 1997.
The April–June 2012 data were among the fresher
PDO and ONI (1996-2013)
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Figure 9. Time series of monthly values of the Northern Copepod Anomaly and Southern Copepod Anomaly. The copepod data are from biweekly sampling at station NH-5 along the Newport Hydrographic Line.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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in spring and summer 2012 do not appear to have been a result of low nutrient availability as nutrient concen-trations were average.
In contrast to the stormy conditions observed in early 2012, ocean conditions in early 2013 along Trini-dad Head Line reflect the effects of a relatively dry win-ter marked by unusually consistent, extended periods of upwelling favorable winds, and relatively infrequent storms of short duration. Intense upwelling throughout April resulted in the coldest, saltiest water observed on the shelf during the time series; conditions over the shelf remained cold and salty relative to spring 2012 (fig. 10). Since the onset of intense upwelling, average chloro-phyll concentrations in the upper water column have remained relatively low (fig. 6).
In 2012 the copepod assemblage over the northern California shelf included relatively few northern neritic species, and high species diversity reflecting the preva-
Southern Copepod Index was predominately negative throughout much of the 2011 to 2013 period (fig. 9).
Northern California Current: Trinidad Head Line
Consistent with the Newport Hydrographic Line, observations along the Trinidad Head Line indicated that coastal waters off northern California were affected by strong downwelling and freshening during a series of storms in spring 2012 (fig. 10). Storm activity con-tinued to affect waters off northern California through the spring and into summer, with northward wind and rain events occurring into July. Chlorophyll concentra-tions in the upper water column remained very low over the shelf throughout 2012 (figs. 6 and 10), save for a modest bloom that developed in early fall (fig. 10). This trend was apparent along the entire line, out to approxi-mately 50 km offshore. Low chlorophyll concentrations
78
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(C)
33.0
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ity (p
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chl (
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da[k] - year.idx[length(year.idx) - 2]
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(ml/l)
day of year (ticks at f irst of month)Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 10. Hydrographic and ecosystem indicators at mid-shelf along the Trinidad Head Line (station TH02, 75 m depth). Panels from top to bottom show near-bottom (60 m) temperature, near-bottom (60 m) salinity, mean chl a concentration over the upper 30 meters of the water column, and near- bottom (60 m) dissolved oxygen concentrations. Grey symbols indicate historical observations (2006–11), open circles indicate observations during 2012, and closed symbols indicate observations in 2013.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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Central California2In January 2012 surface values were colder and salt-
ier due to upwelling winds in late 2011. However, salin-ity values returned to average by June (fig. 12). Surface temperatures remained lower than average until fall. At 100 m anomalous high salinity and low temperature values persisted from January to May, after which they became average to above average for the remainder of
lence of “southern” and “offshore” taxa over the shelf (fig. 11). Northern neritic taxa were modestly more abundant in late spring and summer, but southern taxa were displaced from the shelf only for a brief period in summer 2012. Coupled trends in the copepod assem-blage (declining biomass of southern and oceanic taxa and increasing biomass of northern neritic species) in early 2013 were consistent with expected effects of phys-ical forcing and patterns observed to the north (Newport Hydrographic Line).
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Figure 11. Anomalies (from the 2008–13 mean) in biomass and species richness of the copepod assemblage at mid-shelf on the Trinidad Head Line (station TH02, 75 m depth). Top: Biomass anomaly of dominant northern neritic copepods (dominated by Pseudocalanus mimus, Calanus marshallae, and Acartia longiremis). Middle: Biomass anomaly of southern copepods (neritic and oceanic taxa combined; domi-nated by Acartia tonsa, Acartia danae, Calanus pacificus, Ctenocalanus vanus, Paracalanus parvus, Clausocalanus spp., and Calocalanus spp.). Bottom: species richness anomaly.
See supplement for HF radar data and description of surface current patterns in the Central California region.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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northeast Pacific (PDO, fig. 2). Mixed-layer temperatures since the 1998/99 ENSO have been decreasing but not significantly. Mixed-layer salinities have been increasing over the last two years; this increase reflected a similar increase of the NPGO (fig. 2). Areas of the CalCOFI study domain within the California Current and coastal areas affected by it saw the increase in salinity values. The increase in salinity is primarily observed in those areas of the CalCOFI study domain that are affected by the California Current. The salinity signal was not observed in the offshore areas of the CalCOFI domain that repre-sent the edge of the North Pacific Gyre (fig. S6).
Concentrations of nitrate were close to long-term averages, except for above average spring 2013 values (fig. 13). The distinctive increase of nitrate at the σt 26.4 kg/m3 isopycnal from 2009 to 2012 noted in Bjorkstedt et al. 2012 has returned to near-mean values over the last
the year. Surface chlorophyll was above average during January–February but was below average in the spring and continued to decrease to the lowest values on record by June (fig. 12). At 100 m chlorophyll was average to above average from January to August.
In early 2013, upwelling was significantly stronger than 2012, with the surface salinity and temperature near their maximum and minimum values respectively by April (fig. 12). Surface chlorophyll values increased from below average values in January to mean values by April. At depth, the relationships were similar to those at the surface (fig. 12).
Southern California The 2012 mixed-layer temperatures continued to be
mostly below long-term averages in southern California (fig. 13), consistent with the trends across much of the
J F M A M J J A S O N D10
12
14
16
18
Surfa
ce T
empe
ratu
re
C
Month
Monterey Bay Temperature C
2013 2012 1990-2011 Mean Previous Years
J F M A M J J A S O N D32.5
33
33.5
34
Surfa
ce S
alin
ity p
su
Month
Monterey Bay Salinity psu
2013 2012 1990-2011 Mean Previous Years
J F M A M J J A S O N D0
2
4
6
8
10
Surfa
ce C
hlor
ophy
ll m
g m
-3
Month
Monterey Bay Chlorophyll mg m-3
2013 2012 1990-2011 Mean Previous Years
J F M A M J J A S O N D8
9
10
11
12
13
14
100m
T
empe
ratu
re
C
Month
Monterey Bay Temperature C
2013 2012 1990-2011 Mean Previous Years
J F M A M J J A S O N D33.2
33.4
33.6
33.8
34
34.2
100m
S
alin
ity p
su
Month
Monterey Bay Salinity psu
2013 2012 1990-2011 Mean Previous Years
J F M A M J J A S O N D0
0.2
0.4
0.6
0.8
100m
C
hlor
ophy
ll m
g m
-3
Month
Monterey Bay Chlorophyll mg m-3
2013 2012 1990-2011 Mean Previous Years
Figure 12. Temperature (top panels), salinity (middle panels) and chlorophyll concentration (bottom panels) at the surface (left hand column) and at 100 m (right hand column) observed at the M1 mooring.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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Anomalies of zooplankton displacement volume, a proxy for zooplankton biomass, are only available up to the fall of 2012 (fig. 14, lower panel). Values during 2012 were significantly greater than long-term averages, comparable to values observed during the 1980s and the 1999 La Niña period. These patterns were largely driven by very high abundance of salps and pyrosomes during 2012.
Baja California (Investigaciones Mexicanas de la Corriente de California, IMECOCAL)
Consistent with the observations from 2011–12 (Bjorkstedt et al. 2012), temperatures remained cooler than average in 2012–13. In fact, the three coolest SST values since 1998 occurred in 2011, 2012, and 2013. As well, surface waters continued to be fresher through spring of 2013 but were slightly more saline than that of 2011 (fig. 15). Chlorophyll off Baja California was near average throughout 2011–13, with the exception
12 months. Nitrate anomalies at the isopycnal were 1.8 µM during July 2012, the highest value observed over the last 29 years, but dropped to 0.9 µM in the spring of 2013 (data not shown).
In the CalCOFI region (fig. 1) concentrations of chlorophyll were similar to long-term averages (fig. 14) for all four cruises covered by this report. At the edge of the North Pacific Central Gyre, concentrations of chlorophyll were still above long-term averages while the depth of the subsurface chlorophyll maximum dropped from 50 m to 75 m (fig. S7). Similar patterns were observed in the southern California Current region (fig. S7). Concentrations of chlorophyll, however, were at or below long-term averages in the northern Cali-fornia Current region and in the coastal areas (figs. 6 and S7). Values of primary production were below or at long-term averages during the summer and fall of 2012 but substantially above long-term averages during the first half of 2013.
-30
-20
-10
0
10
20
30
1984 1988 1992 1996 2000 2004 2008 2012
Ano
mal
y (m
) .
D - Nitracline Depth
B - Mixed Layer Salinity Anom
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
Ano
mal
y .
A - Mixed Layer Temp Anom.
-2
-1
0
1
2
3
Ano
mal
y (˚C
) .
-2
-1
0
1
2
3
4
1984 1988 1992 1996 2000 2004 2008 2012
Ano
mal
y (m
) .
C - Nitrate Anom.
Figure 13. Property anomalies for the mixed layer (ML) of the CalCOFI standard grid: A – ML temperature anomaly, B – ML salinity anomaly, C – ML nitrate con-centration anomaly and D – nitracline depth anomalies which are negative when the nitracline is closer than expected to the surface and positive when deeper than long-term averages. Data from individual CalCOFI cruise data are plotted as open diamonds. The thin solid lines represent the annual averages, the dotted lines the climatological mean, which in the case of anomalies is zero and the straight solid lines, when present, long-term linear trends. In panel C, nitrate, solid symbols are spring values.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
49
herbivorous filter-feeding forms, include salps, doliol-ids, pyrosomes, and appendicularians. The carnivorous forms are represented by a variety of taxa, such as jel-lyfish (e.g., Hydromedusae, Schyphomedusae, siphono-phores), pelagic snails (pteropods, heteropods), and arrow worms (chaetognaths).
Northern CaliforniaCatches of tunicates in the NWFSC pelagic survey
were very low (zero in many cases) from June 2004 until June 2010, after which salp densities spiked over a short period, reaching a maximum of 3400 individu-als per 106 cubic meters of water sampled by August of
of a single high and positive anomaly during spring of 2012 (fig. 16).
Zooplankton displacement volume remained high during 2012 through February 2013 continu-ing an eight-year period of higher than average values (fig. 17). However, euphausiid density was below aver-age between the springs of 2011 and 2012. Copepods have been anomalously abundant since 2010 except for the 2011/2012 winter values.
GELATINOUS ZOOPLANKTONIn this report gelatinous zooplankton are divided into
two categories: herbivores and carnivores. Tunicates, the
-40-30-20-10010203040506070
Jan-84 Jan-88 Jan-92 Jan-96 Jan-00 Jan-04 Jan-08 Jan-12
Chl
a (
mg
m-2
)
A
-300
-200
-100
0
100
200
300
400
500
Jan-84 Jan-88 Jan-92 Jan-96 Jan-00 Jan-04 Jan-08 Jan-12
Inte
gr. P
rim
. Pro
d. (m
g m
-2 d
-1) B 880
-2
-1
0
1
2
1984 1988 1992 1996 2000 2004 2008 2012
Ln
Zoo
_Dis
plac
emen
t
C
Figure 14. CalCOFI region averages for standing stocks of chlorophyll-a (A) and rates of primary production (B) both integrated to the bottom of the euphotic zone and (C) the log of zooplankton displacement volume, all plotted against time.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
50
1998 2000 2002 2004 2006 2008 2010 2012−1.5
−1
−0.5
0
0.5
1
1.510m chlorophyll anomalies
Chl
orop
hyll
[mg/
m3 ]
Time [years]
Figure 15. Mixed layer temperature anomaly and mixed layer salinity off Baja California Peninsula (IMECOCAL). Each bar represents each cruise conducted.
Figure 16. Anomaly time series of 0–100 m integrated chlorophyll a off Baja California Peninsula (IMECOCAL). Each bar represents each cruise conducted.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
51
In 2012, the numbers of S. fusiformis, other salp spe-cies, and pyrosomes in the core region of the SWFSC rockfish recruitment survey (roughly Point Reyes to Point Piños) far exceeded previously recorded values (fig. 19) (Bjorkstedt et al. 2012), although the abun-dance of Thetys vagina remained well within the range of previously observed blooms (fig. 19). The largest salp and pyrosome catches were in the southern region of the expanded coast-wide rockfish recruitment survey (fig. 19). Although there is no baseline data to com-pare these trawl survey catches, they are consistent with accounts of high salp abundances in this region during 2012 (Bjorkstedt et al. 2012). By spring 2013 salps, pyro-soma, and Thetys vagina were near typical values in the core region and reduced in the southern region (fig. 19).
In 2012, within the rockfish recruitment survey’s core region, large salp catches mostly occurred at offshore sta-tions, and the magnitude of the catches were substan-tially larger than the long-term average (fig. 20). Salp
2010. Densities remained high into early 2011 and then tapered to near normal low catches in 2012 (fig. 18).
Densities of the two dominant larger medusa species in this region, Chrysaora fuscescens and Aequorea spp., have been monitored as part of a pelagic trawl survey con-ducted every June and September since 1999 (Suchman et al. 2012)(see supplement for data collection). Catches of both species returned to a more typical level in June 2012, following below-average catches for the last two years (fig. S8). In September 2012, catches of both spe-cies were similar to 2011, with densities of C. fuscescens being approximately an order of magnitude higher than those of Aequorea, similar to that seen earlier by Such-man et al. 2012.
Central CaliforniaThe major contributors to the herbivorous tunicate
catch off Central California were the salps, Thetys vagina and Salpa spp., as well as pyrosomes, Pyrosoma spp.
Figure 17. Time series of anomalies of zooplankton volume and group abun-dances for the Baja California Peninsula (IMECOCAL) region. Each bar repre-sents a single cruise and open circles represent indicate cruises that did not take place or were omitted due to limited sampling.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
52
the last two years (fig. 17). However high-density patches occurred in discrete locations, such as in Vizcaino Bay. Carnivorous forms were present in similar abundance and composition as the 2011 reported values. Medusae continued to have positive anomalies while chaetognaths maintained negative anomalies. In contrast, the siphono-phores shifted from the high positive anomalies in 2010 to a strong negative anomaly in February 2012.
SYNTHESIS OF OBSERVATIONS ON HIGHER TROPHIC LEVELS
Pelagic Fishes off Oregon and Washington Time series plots of yearly abundance data are pre-
sented for each of the five most dominant and consis-tently collected forage species (jack mackerel, Trachurus symmetricus, Pacific sardine, northern anchovy, Pacific herring, Clupea pallasii, and whitebait smelt, Allosmerus elongates) (fig. 22) measured during the NWFSC-NOAA Bonneville Power Administration (NOAA/BPA) survey surface trawls. The survey also captures Pacific mackerel, Scomber japonicas, shown as well. The survey extends from Cape Flattery in northern Washington to Newport in central Oregon from June to September. Although other forage species are caught in these surveys, these five six species represent the bulk of the forage fish catch in surface waters. They include migratory species (Pacific
catches during 2013 have returned to more typical val-ues observed in the survey. The summer salmon survey (fig. 1) that immediately followed the rockfish recruit-ment survey did not encounter extreme salp concentra-tions in 2012 and 2013, but this was likely due to the predominantly inshore sampling (data not shown).
The observed abundances of the jellyfish C. fuscescens during late spring of 2012 and 2013 were within the range of variability noted since 1990 (fig. 19). As in pre-vious years, the largest catches of C. fuscescens occurred within the Gulf of the Farallones while the largest catches of Aurelia spp. occurred inside Monterey Bay’s upwelling shadow (Graham and Largier 1997).
Southern CaliforniaThere were large concentrations of gelatinous zoo-
plankton encountered off southern California (predom-inantly tunicates). A proxy for the abundance of larger, mostly gelatinous, zooplankton is the difference between total zooplankton displacement volume (ZDV) and small fraction ZDV (fig. 21A) leaving the large fraction ZDV (fig. 21B). The latter fraction was substantially increased during 2011 to 2012 compared to the previous decade.
Baja CaliforniaAt the southern extent of the CCS off Baja, herbiv-
orous tunicates maintained average abundances during
0
500
1000
1500
2000
2500
3000
3500
4000
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
May
June
July
Aug
Sept
Density
(no. 106 m
3 )
2004 2005 2006 2007 2008 2009 2010 2011 2012
Figure 18. Densities of salps (mostly Thetys vagina and Salpa fusiformis) observed in the NWFSC pelagic rope trawl surveys off the coast of Oregon and Washington in May–September, from 2004 to 2012.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
53
Salps
1980 1985 1990 1995 2000 2005 2010 2015012345678
CoreSouth
Pyrosoma
1980 1985 1990 1995 2000 2005 2010 2015
Mea
n lo
g-tra
nsfo
rmed
cat
ch
0
1
2
3 CoreSouth
Thetys
Year1980 1985 1990 1995 2000 2005 2010 2015
0
1
2
3 CoreSouth
1980 1985 1990 1995 2000 2005 2010 20150.00.20.40.60.81.01.21.41.6
Aurelia Chrysaora
Jellyfish
Figure 19. Geometric mean of catches per unit volume of gelatinous zooplankton from the central California rockfish recruitment survey.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
54
(Emmett et al. 2005) so may experience intra-annual variability in abundance that is not captured by sampling two times per year. Ultimately, a number of forage fish are at reduced abundance (fig. 22, survey D, fig. 1). In 2012, Pacific herring, and Pacific sardine were at their lowest observed abundances since the start of the survey in 1998. Northern anchovy abundance was lower than it has been since 2002 (fig. 22).
sardines and some northern anchovies) that may spawn off the Pacific Northwest or migrate from California (Emmett et al. 2005; Litz et al. 2008). Jack mackerel serve as a forage fish at younger ages but off Oregon and Washington are too large to be fed upon by most predators such as seabirds or adult rockfishes. Herring and whitebait smelt are likely spawned locally. A num-ber of these species have seasonal trends in abundance
122°0'0"W123°0'0"W124°0'0"W
38°0
'0"N
37°0
'0"N
122°0'0"W123°0'0"W
2012 Salpa spp. 2012 Pyrosomes
Avg ln0.00 - 1.00
1.00 - 2.00
2.01 - 3.00
3.01 - 4.00
4.01 - 5.00
5.01 - 6.00
6.01 - 7.00
7.01 - 8.00
8.01 - 9.00
9.01 - 11.00
122°0'0"W123°0'0"W124°0'0"W
38°0
'0"N
37°0
'0"N
122°0'0"W123°0'0"W
1987-2001 Salpa spp. 1987-2001 Pyrosomes
Avg ln0.00 - 1.00
1.00 - 2.00
2.01 - 3.00
3.01 - 4.00
4.01 - 5.00
5.01 - 6.00
6.01 - 7.00
7.01 - 8.00
8.01 - 9.00
9.01 - 11.00
122°0'0"W123°0'0"W124°0'0"W
38°0
'0"N
37°0
'0"N
122°0'0"W123°0'0"W
2012 Salpa spp. 2012 Pyrosomes
Avg ln0.00 - 1.00
1.00 - 2.00
2.01 - 3.00
3.01 - 4.00
4.01 - 5.00
5.01 - 6.00
6.01 - 7.00
7.01 - 8.00
8.01 - 9.00
9.01 - 11.00
Figure 20. Distribution of the historical geometric mean of catches of salps from central California rockfish recruitment survey, 1987–2011, and those from 2012.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
55
feeding conditions for juvenile salmon during the 2013 out migration (see supplemental results, fig. S9).
In the June NOAA/BPA surveys from 2008 and 2009, catches of juvenile spring-run Chinook salmon were high, with record high catches in 2008. Although catches in June 2011 were poor, catches in June 2012 were high, ranking second among the 15 years of surveys (fig. 24) suggesting excellent nearshore forage. However, catches of coho salmon in September 2012 survey were relatively low (fig. 24).
Pelagic Fishes Off Central California Trends in both 2012 and 2013 showed higher pro-
ductivity for the species and assemblages that tend to do better with regionally cool, high southward transport conditions, including juvenile rockfish, market squid, and krill (predominantly Euphausia pacifica and Thysanoessa spinifera) (fig. 25, see supplement for additional results). In 2012, juvenile rockfish catches were above average, as they have been in most years since 2008, and in 2013 the highest catches of juvenile rockfish in the time series of the survey were recorded, with huge numbers of juvenile
The ichthyoplankton and juvenile fish communities along the Newport Hydrographic Line off the coast of Oregon in May 2012 were similar to the average assemblages found in the same area and month dur-ing the previous five years both in terms of mean con-centrations and relative concentrations of the dominant taxa (fig. 23). However, larval myctophids were found in the highest concentration in July 2012 of the five-year time series, while larval northern anchovy were found in higher concentrations (>3x) in July 2012 than in the same month in 2007–10. In addition, concentra-tions of the dominant taxa of juvenile fish were higher in July 2012 than in the same month in the previous five years, largely due to the abnormally high concentra-tion of juvenile rockfish found in July 2012 (>10x that of any other year in 2007–11). No juvenile Pacific hake or northern anchovy were collected from the midwater trawl samples in May or July 2012, although age 1 and adult specimens of both species were found. Similarly, the biomass of ichthyoplankton in 2013 from winter collections along the Newport Hydrographic Line were above average (1998–2013), predicting average-to-good
0
50
100
150
200
250
300
350
400
1984 1988 1992 1996 2000 2004 2008 2012
Zoo
Dis
plac
emen
t Vol
ume
A1136
0
200
400
600
800
1000
1984 1988 1992 1996 2000 2004 2008 2012
Zoo
Dis
plac
emen
t Vol
ume
B
0
50
100
150
200
250
300
350
400
1984 1988 1992 1996 2000 2004 2008 2012
Zoo
Dis
plac
emen
t Vol
ume
A1136
0
200
400
600
800
1000
1984 1988 1992 1996 2000 2004 2008 2012
Zoo
Dis
plac
emen
t Vol
ume
B
Figure 21. Zooplankton displacement volume (ml per 1000 m2 seawater) for the small zooplankton fraction (A) and the large fraction (B). The large fraction consists of all organisms whose individual volume is larger than 5 ml. The small fraction is calculated by difference.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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-‐2.5
-‐2
-‐1.5
-‐1
-‐0.5 0
0.5 1
1.5 2
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Anomalies Jack M
ackerel
-‐2
-‐1.5
-‐1
-‐0.5 0
0.5 1
1.5
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Anomalies
Northern An
chovy
-‐3.5
-‐3
-‐2.5
-‐2
-‐1.5
-‐1
-‐0.5 0
0.5 1
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Anomalies
Pacific Herrin
g
-‐2.5
-‐2
-‐1.5
-‐1
-‐0.5 0
0.5 1
1.5 2
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Anomalies
Pacific M
ackerel
-‐2
-‐1.5
-‐1
-‐0.5 0
0.5 1
1.5 2
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Anomalies
Pacific Sardine
-‐2
-‐1.5
-‐1
-‐0.5 0
0.5 1
1.5 2
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Anomalies Whiteba
it Sm
elt
Figu
re 2
2.
Gro
up a
nom
alie
s of
cat
ches
per
uni
t vo
lum
e fo
r th
e si
x m
ost
com
mon
for
age
fish
colle
cted
dur
ing
the
NW
FSC
pel
agic
rop
e tr
awl s
urve
y, 1
998–
2012
.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
57
0
200
400
600
800
1000
2007
20
08
2009
20
10
2011
20
12
Mean concentration (no. 10-3 m-3)
Oth
er
Myc
toph
ids
Roc
kfis
h N
orth
ern
anch
ovy
Flat
fish
May
0
500
1000
1500
2000
2500
3000
2007
20
08
2009
20
10
2011
20
12
Mean concentra*on (no. 10-‐3 m-3)
July
Larv
ae
0
100
200
300
400
500
600
700
800
2007
20
08
2009
20
10
2011
20
12
Mean concentration (no. 10-6 m-3)
Myc
toph
ids
Roc
kfis
h Fl
atfis
h
May
*
0
500
1000
1500
2000
2500
3000
2007
20
08
2009
20
10
2011
20
12
Mean concentration (no. 10-6 m-3)
July
Juve
nile
s
Figu
re 2
3.
Mea
n co
ncen
trat
ions
of t
he d
omin
ant t
axa
for
fish
larv
ae (l
eft)
and
juve
nile
s (r
ight
) col
lect
ed in
May
and
Jul
y in
200
7–12
alo
ng th
e N
ewp
ort H
ydro
grap
hic
(NH
) lin
e of
f the
coa
st o
f Ore
gon
(44.
65°N
, 12
4.41
–125
.36°
W).
No
mid
wat
er t
raw
l sam
ple
s w
ere
colle
cted
for
juve
nile
s in
May
201
0.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
58
Pelagic Fishes Off Southern California The spring coastal pelagic species survey showed
sardine egg densities were similar in 2012 to those measured in 2011 (methods in supplement, fig. S11). However, densities of sardine eggs and anchovy eggs were lower than those measured in most years since 1997 (fig. 27). Jack mackerel egg densities were similar to those measured during most other years in the time series. In 2013, sardine, anchovy, and jack mackerel egg densities were similar to those measured in the previous two years (fig. 28).
An examination of larval captures from the CalCOFI surveys 1951–2011 demonstrated similar trends (fig. 29). Larval Pacific sardine catches have been relatively sta-ble over recent decades, minus low catches in 2004 and 2010. In general, larval northern anchovy were captured in greater densities than Pacific sardine before the mid-1990s. However, larval northern anchovy catches have declined substantially since the early 1980s (fig. 29). Unfortunately, data on larval catch densities beyond 2011 have not yet been enumerated.
SEABIRDS AND MAMMALS3
Breeding Success and Diets of Seabirds at Yaquina Head
Examination of the common murre, Uria aalge, diets indicates that smelts were the predominant prey avail-able to the seabirds (fig. S12). When paired with the results from the forage observations in northern CCS, this diet composition was similar to changes in the avail-able proportions in the forage community (fig. 22). The breeding success of common murre remained low relative to 2007–10 (fig. 30, see supplement for data methods). Observations indicate that the reduced
rockfish of all species (as well as young-of-year ground-fish of other species, such as Pacific hake, flatfishes, and lingcod, Ophiodon elongates) encountered throughout both the core and expanded survey areas. Market squid and krill were at very high levels in 2012 and 2013 as well. Although more northern anchovy were encoun-tered in 2013 than in the previous five years, catches of both that species and of Pacific sardine remained well below long-term averages. As with the 2012 results, 2013 continued to indicate a pelagic micronekton community structure dominated by cool-water, high transport, high productivity forage species (juvenile groundfish, krill, and market squid (see Ralston et al. 2013).
Later in the summers of 2010–12 a surface trawl survey was used to characterize juvenile salmon and the micronekton from central California to Newport, Oregon. The summer of 2012 continued a period of extremely low abundance for northern anchovy, Pacific sardine, and Pacific herring. The survey caught no adult northern anchovy in 2011 or 2012 and very few in 2010; no Pacific sardine in 2012 and very few in the two years before that; and very few Pacific herring in all three years, 2010–12. Other important forage fishes such as surf smelt, Hypomesus pretiosus, and whitebait smelt were more abundant and were consistently taken in all three years since 2010, but these two osmerid species were primarily encountered in the northern portion of the study area. Market squid was very abundant in all three years and was encountered throughout the study area. Sub-yearling juvenile Chinook salmon (80–250 mm fork length, FL) were less abundant in the catches in 2012 than in the previous two years (fig. 26, see sup-plement for results concerning additional age classes). Unlike Chinook salmon, the abundance of juvenile coho salmon (100–300 mm FL) was similar in the summer of 2011 and 2012 (fig. 26). Significantly more juvenile coho salmon were caught in either of those two years than in July 2010.
June
1998 2000 2002 2004 2006 2008 2010 2012
Num
ber p
er k
m to
wed
0
1
2
3
4
5
6
7
September
1998 2000 2002 2004 2006 2008 2010 2012
Num
ber p
er k
m to
wed
0.0
0.5
1.0
1.5
2.0June
1998 2000 2002 2004 2006 2008 2010 2012
Num
ber p
er k
m to
wed
0
1
2
3
4
5
6
7
September
1998 2000 2002 2004 2006 2008 2010 2012
Num
ber p
er k
m to
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Figure 24. Catches of juvenile coho salmon (black bars) and Chinook salmon (white bars) off the coasts of Washington and Oregon.
3In addition to seabird and sea lion observations, cetacean density and abundance on the southern CalCOFI lines was quantified. Results are shown in the supplement.
STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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Figure 25. Long-term standardized anomalies of several of the most frequently encountered pelagic forage species from the central California rockfish recruitment survey in the core region (1990–2012).
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STATE OF THE CALIFORNIA CURRENTCalCOFI Rep., Vol. 54, 2013
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below the long-term means observed for each species. Pelagic cormorants, Phalacrocorax pelagicus, and Brandt’s cormorants, Phalacrocorax penicillatus, experienced near complete breeding failure in 2012. This is the fifth con-secutive year of extremely low reproductive success for Brandt’s cormorants but the first breeding failure for the pelagic cormorant since 2005. Productivity of western gulls (Larus occidentalis) was slightly higher than during 2011, but continued to be among the poorest years on record, marking the fourth consecutive year of very low reproductive success for this species.
Breeding Success and Diets of Seabirds at Castle Rock
In 2012, the first common murre nest at Castle Rock was initiated on 15 May, between 4 and 32 days later than all other years of study. Although the aver-age nest initiation date could not be determined due to
reproductive success was due to increased predation (e.g., eagles, pelicans, vultures).
Breeding Success of Seabirds at Southeast Farallon Islands
Overall breeding success of seabirds during the 2012 breeding season at Southeast Farallon Island can best be classified as an average year for most species. Cas-sin’s auklets, Ptychoramphus aleuticus, which feed primarily on euphausiids, exhibited exceptionally high productiv-ity for the third consecutive year (fig. 31). The average number of chicks fledged per breeding pair was the sec-ond highest on record, and reflected both exceptional fledging success and a high rate of successful double brooding. Among the piscivorus seabirds, productivity of common murres was slightly higher than that observed during 2011 while rhinoceros auklets (Cerorhinca monocerata) and pigeon guillemots declined to values slightly
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Figure 26. Size frequency distributions of (A) Chinook salmon (Oncorhynchus tshawytscha) and (B) coho salmon (O. kisutch) captured by rope trawl in the coastal ocean (~1–20 nautical miles offshore) between southern Oregon and central California in June or July of 2010, 2011, and 2012. Counts are total number (not stan-dardized) of fish captured in each year; proportions are fraction of that total count represented by each bar for each year and species. Different scales used for columns A and B.
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Figure 27. Densities of eggs of Pacific sardine (blue), jack mackerel (red), and northern anchovy (green) collected with the Continuous Underway Fish Egg Sampler (CUFES) along the ship track (black lines) during NOAA spring cruises for 1997 to 2012. The underlying color image shows a monthly composite of satellite AVHRR 1.4 km resolution sea surface temperature (°C) image coincident with the survey period in each year.
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Figure 28. Densities of eggs of Pacific sardine, jack mackerel, and northern anchovy collected with the Continuous Underway Fish Egg Sampler (CUFES) along the ship tracks (red lines) during NOAA coast-wide cruises conducted in spring 2013. The underlying color image shows a monthly composite of satellite AVHRR 1.4 km resolution sea surface temperature (°C) image coincident with the survey period in each year.
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ln (larvae/10
m2 +1)
Anchovy Sardine
Figure 29. Abundance (ln (number /10 m2+1)) of northern anchovy and Pacific sardines captured in oblique tows (bongo net) during spring CalCOFI surveys 1951–2011.
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decreases elsewhere could be affecting our counts; this may be the result of shearwaters declining on some New Zealand islands (Scott et al. 2008).
Productivity and Condition of California Sea Lions at San Miguel Island
California sea lions (Zalophus californianus) are per-manent residents of the CCS, breeding on the Califor-nia Channel Islands and feeding throughout the CCS in coastal and offshore habitats. They are also sensitive to changes in the CCS on different temporal and spa-tial scales and so provide a good indicator species for the status of the CCS at the upper trophic level (Melin et al. 2012). Two indices are particularly sensitive measures of prey availability to California sea lions, pup produc-tion, and pup growth through four months of age. Pup production is a result of successful pregnancies and is an indicator of prey availability and nutritional status of adult females from October to the following June. Pup growth from birth to four months of age is an index of the transfer of energy from the mother to the pup through lactation between June and October, which is related to prey availability to adult females during that time and to survival of pups after weaning. The average number of live pups counted at San Miguel Island in July 2012 was 24,993 (fig. 33). The high live pup count in 2012 suggests that pregnant females experienced good foraging conditions from October 2011 to July 2012.
However, the pup growth index for California sea lions at San Miguel Island indicated that dependent pups were in poor condition by the time they reached four months of age. In October 2012, the average predicted
uncertainties resulting from equipment failure, we con-cluded that nesting began later than usual in 2012 (see supplement for data collection and additional results, fig. S13).
For Brandt’s cormorants, efforts to monitor nest phe-nology and success began in 2011 and baseline under-standing of their reproductive performance is still being developed. Based on nests initiated prior to camera fail-ure in 2012, 71% of first clutches (n = 13) failed during incubation. The failure rate for first clutches was simi-larly high in 2011, with 68% of first clutches failing dur-ing incubation.
At-sea Density of Seabirds off Southern California
Patterns of variability are illustrated in the relative abundance of two species, the sooty shearwater, Puffinus griseus, and Cassin’s auklet expressed as natural log of density sighted (ln [birds km–2 + 1], see supplement for methods). Both species prey upon euphausiid crus-taceans, small pelagic fish, and squid. In 2012, there was nothing unusual in the relative abundance of auklets in any season (fig. 32).
In contrast to the resident auklets, shearwaters were most abundant in the study region during the summer (July–August), with lower relative abundance in spring (April–May). During both seasons in 2012, the relative abundance of shearwaters declined (fig. 32). In 2012, numbers were substantially reduced from a recent peak in both spring and summer in 2010. Changes in shear-water abundance may be related to short or long-term changes in food availability. Alternatively, population
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Year Figure 30. Anomalies of reproductive success (fledglings per breeding pair) of common murre at Yaquina Head.
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Standardized productivity anomalies (annual productivity - long term mean) for 8 species of seabirds on SEFI, 1971-2012. The dashed lines represent the 80% confidence interval for the long term mean.
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Figure 31. Standardized productivity anomalies (annual production–long term mean) for 8 species of seabirds on Southeast Farallon Island, 1971–2012. The dashed lines represent the 80% confidence interval for the long-term mean. Abbreviations are used fro Brandt’s cormorant (BRCO), pelagic cormorant (PECO), western gull (WEGU), common murre (COMU), pigeon guillemot (PIGU), rhinoceros auklet (RHAU), Cassin’s auklet (CAAU), and storm petrel (ASSP).
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nificantly underweight (females, mean = 13.6 kg, SE = 0.55; males, mean = 16.2 kg, SE = 0.69) (fig. 34); an esti-mated 12 kg and 14.4 kg below the long-term average for females and males, respectively. A longitudinal anal-ysis of pup daily growth rates of branded pups between four and seven months of age showed significantly lower daily growth rates compared to other years for female and male pups (fig. 34). In both October and February, the mean weights for the 2012 cohort were similar to
weights of four-month-old female (13.0 kg, SE = 0.14) and male (14.5 kg, SE = 0.20) pups were significantly lower compared to the long-term mean for female and male pups (females, mean = 17.4 kg, SE = 0.35; males, mean = 20.2 kg, SE = 0.43) (fig. 34). Average October weights of California sea lion pups have been declining since 2008 but the mean weights for the 2012 cohort were significantly lower than the previous four years. By February 2013, at 7 months of age, pups remained sig-
Figure 32. Changes in resident Cassin’s auklet (upper panel) and migratory Sooty Shearwater (lower panel) relative abundance (natural log of birds km–2) on 90 CalCOFI/CCE-LTER surveys, May 1987–July 2012. Stacked bars denote seasonal density estimates, with 2 Locally Weighted Regression (LOWESS) smoothing lines on summed annual estimates shown to illustrate short-term (bandwidth = 0.3, solid) and long-term (bandwidth = 0.8, dashed) variability.
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of investigation were initiated to explain the Unusual Mortality Event, one focusing on disease in pups or their mothers and the other on a shortage of food available to lactating females (see supplement for comment).
DISCUSSIONIn 2012 the basin-scale indices and conditions from
regional surveys indicate that oceanographic character-istics of the CCS were similar to recent cool years. The PDO signaled a continued pattern of cool SST and the NPGO was consistent with strong southward transport (fig. 2). The MEI demonstrated a short-lived switch to positive values in the summer of 2012, but was not suf-ficiently strong to elicit a response in CCS SST. Dur-ing winter of 2011/2012, upwelling in the northern CCS was substantial, especially north of 39˚N (fig. 3). However, in the north, upwelling winds weakened in midwinter and remained weak until resuming to near-average values in May. In the south, upwelling remained strong. Regional hydrographic studies also demonstrated that conditions were not too dissimilar from conditions observed since 2007 for SST or salinity (figs. 7, 10, 12, 13, and 15).
Winter of 2011/2012 presented an uncharacteristic upwelling period and strong southward transport lead-ing into 2012. Between 36˚N and 45˚N, the winds in December 2011 were unusual because the expected downwelling-producing winds were replaced by mod-
the 1997 cohort, as were the daily growth rates between October and February. The 1997 cohort was impacted by a strong El Niño event that prevailed in the Cali-fornia Current between May 1997 and May 1998. The oceanographic conditions associated with the El Niño resulted in poor foraging conditions by reducing prey availability for lactating California sea lion females and consequently, their dependent pups were in poor condi-tion (Melin et al. 2012; Melin et al. 2010).
In addition to poor condition of pups on the rook-ery at San Miguel Island, high numbers of emaciated pups began stranding on southern California beaches in January 2013, indicating that pups were weaning up to three months earlier than normal. High levels of strand-ings continued into April with three times the nor-mal level of strandings during the four-month period (http://www.nmfs.noaa.gov/pr/health/mmume/cali-forniasealions2013.htm). Although early weaning of pups and emaciated pups at the rookeries could be due to high mortality of adult females, there was no increase in strandings of lactating females during this period and emaciated pups were observed suckling robust females, suggesting that the cause for the poor condition of the pups was not related to mortality of their mothers. In response to the poor condition of pups at the rookeries and the high level of strandings, the National Marine Fisheries Service declared an Unusual Mortality Event of California sea lion pups on March 25, 2013. Two lines
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Year Figure 33. The average number of live California sea lion pups counted at San Miguel Island, California, 1997–2012 in late July when surviving pups were about 6 weeks old. Error bars are ±1 standard deviation.
http://www.nmfs.noaa.gov/pr/health/mmume/californiasealions2013.htm
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erate upwelling-producing winds, while north of 45˚N downwelling winds weakened (fig. 3). The upwelling and weakened downwelling winds resulted in coastal sea levels that suggested transport was more southward than had been observed in the past 45 Decembers (fig. 4). This southward transport was corroborated by HF radar showing anomalous equatorward surface velocities north of Cape Blanco in December 2011 (fig. 5). Consistent with increased southward transport, the northern cope-pod index calculated for the Newport Hydrographic Line had the largest ever values of northern copepod species during winter 2011/2012 (fig. 9). Interestingly, there was not a similar increase in northern copepods at Trinidad Head, however, an examination of HF radar (fig. 5) suggests that the surface source waters at Trinidad Head during winter 2011 may have been derived from immediately south of Cape Mendocino.
We acknowledge there are limitations and differences between survey designs represented here, but from our available observations, a CCS-wide pattern emerged with reduction of two primary forage fishes, namely northern anchovy and Pacific sardine (as well as Pacific herring where sampled in central and northern Cali-fornia). The abundances of these species along the CCS were near record minima in surveys. In the CalCOFI survey region, egg densities for both northern anchovy and Pacific sardine were low indicating a possible reduc-tion in the spawning stock and/or the spawning stock resided outside the study region (figs. 27 and 28). Sim-ilarly, these fishes were caught in reduced numbers in central and northern California (figs. 22 and 25).
Lower observed abundance in northern anchovy in 2012 may have been an extension of a declining trend. Catches of larval anchovy in the southern California waters have declined over the last three decades with the lowest densities recorded in the recent five years ending in 2011 (fig. 29). This pattern indicates either a reduction in spawning stock biomass, early survival, or increased advection from the region (Bakun and Parrish 1982). What made 2012 particularly intriguing relative to forage, was not only that northern anchovy abundance was reduced across the CCS but that Pacific sardine and Pacific herring were at low abundances as well. That 2012 saw a reduction in the clupeiform forage commu-nity along the coast suggests that common factors could
Figure 34. Top panel: Predicted average weights of 4 month old female (cir-cle) and male (triangle) California sea lion pups at San Miguel Island, Califor-nia, 1997–2012 and long-term average between 1975 and 2012 for females (solid line) and males (dashed line). Error bars are ±1 standard error. Middle panel: Predicted average weights of 7 month old female (circle) and male (tri-angle) California sea lion pups at San Miguel Island, California, 1997–2012 and long-term average between 1975 and 2012 for females (solid line) and males (dashed line). Error bars are ±1 standard error. Bottom panel: Predicted aver-age daily growth rate of female (circle) and male (triangle) California sea lion pups between 4 and 7 months old at San Miguel Island, California, 1997–2012. Error bars are ±1 standard error.
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feed, and may even spawn, at and beyond the shelf break (Kramer and Ahlstrom 1968; Smith 1972). In part, the northern anchovy may be held offshore by advection (Bakun and Parrish 1982). This is clear in the central California region where, even during the cool, produc-tive conditions that benefit northern anchovy produc-tion (Lindegren et al. 2013), the northern anchovy are not abundant in the survey region (fig. 1). It is only when upwelling subsides, or during relatively unproduc-tive years associated with reduced winds, that northern anchovy become increasingly available to the trawls and the inshore environment. Pacific sardine, as well, reside more offshore at or beyond the shelf break (Kramer 1970). By contrast, the fishes reliant on productive, cool waters inshore have had improved production recently. These fishes, such as rockfish, market squid, lingcod, and others, reside largely in the productive cool nearshore waters during upwelling periods.
While unsubstantiated in the CCS, there is a poten-tial that dense salp concentrations in central and south-ern California (but not so far sout